E-cadherin abnormalities resulting from CPG methylation promoter in metastatic and nonmetastatic oral cancer.

BACKGROUND: This study aims to compare the alterations in the methylation profiles of E-cadherin in oral cancer, especially in tumors with lowest metatastic potential. METHODS: Nine oral verrucous carcinomas (VCs), 20 oral well-differentiated squamous cell carcinomas without lymph node involvement (SCC-pN0), and 17 with lymph node involvement (SCC-pN+) were analyzed using methylation-specific polymerase chain reaction and immunohistochemical expression of E-cadherin gene. RESULTS: The immunohistochemical expression of E-cadherin in VC was significantly higher (p = .016) when compared with SCC-pN0 and SCC-pN+ groups. The E-cadherin gene methylation was not correlated with its abnormal immunohistochemical expression in VC and SCC-pN0. All tumors of the SCC-pN+ group with unmethylated E-cadherin gene showed significant loss of E-cadherin immunoexpression (p = .044). CONCLUSIONS: The E-cadherin gene methylation presence in tumors with lowest invasive and metastatic potential, such as VC, suggests the early involvement of this epigenetic event in the multistep progression of the oral carcinogenesis.

Oral verrucous carcinoma: a retrospective study in São Paulo Region, Brazil.

Oral verrucous carcinoma (OVC) is a rare variant of squamous cell carcinoma with a characteristic morphology and specific behavior. To date, few studies are available focusing the prevalence and clinicopathologic features of the oral verrucous carcinoma in Brazilian population. A total of 3,500 primary oral well-differentiated squamous cell carcinoma surgically excised in the A.C. Camargo Cancer Hospital and Amaral Carvalho Cancer Hospital, Brazil, from 1980 to 2000 were retrospectively reviewed. Twenty cases of verrucous carcinomas were identified, most of them occurring in older male with age above the sixth decade, the sites frequently affected being the lower lip and the hard palate. Microscopically, the tumor showed a heavily keratinized lesion with compressive invasion pattern, little atypia, and free surgical margins. The local recurrence was verified in 38.5% of the patients with oral verrucous carcinoma; however, regional recurrence and distant metastasis were not verified. The results suggest that, although it is less frequent and with excellent prognosis, the verrucous carcinoma presents a potential for local recurrence that should be considered during the surgical planning of this neoplasm in the oral cavity.